scholarly journals Mapping and inventorying active rock glaciers in the Northern Tien Shan (China) using satellite SAR interferometry

2016 ◽  
Author(s):  
Xiaowen Wang ◽  
Lin Liu ◽  
Lin Zhao ◽  
Tonghua Wu ◽  
Zhongqin Li ◽  
...  
Keyword(s):  
Quantitative Information ◽  
Google Earth ◽  
Tien Shan ◽  
Sar Interferometry ◽  
Western China ◽  
Mountain Ranges ◽  
North East ◽  
Optical Images ◽  
Rock Glaciers ◽  
Northern Tien Shan

Abstract. Rock glaciers are widespread in the high mountains of western China. However, they have not been systematically investigated for more than two decades. In this study, we propose a new method that combines SAR interferometry and optical images from Google Earth to map active rock glaciers (ARGs) in the Northern Tien Shan (NTS) in China. We compiled an inventory that includes 261 ARGs and quantitative information about their locations, geomorphic parameters, and down-slope velocities. Our inventory shows that most of the ARGs are moraine-derived (68 %) and facing north-east (56 %). The altitude distribution of ARGs in the western NTS is significantly different from those located in the eastern part. The down-slope velocities of the ARGs vary significantly in space, with a maximum of about 114 cm yr−1 and a mean of about 37 cm yr−1. Using the ARG locations as a proxy for the extent of alpine permafrost, our inventory suggests that the lowest altitudinal limit for the presence of permafrost in the Northern Tien Shan is about 2500–2800 m, a range determined by the lowest ARG in the entire inventory and by a statistics-based estimation. The successful application of the proposed method would facilitate an effective and robust effort to map rock glaciers over major mountain ranges and provide important datasets to improve mapping and modeling permafrost distribution in vast western China.

scholarly journals Mapping and inventorying active rock glaciers in the northern Tien Shan of China using satellite SAR interferometry

2017 ◽  
Vol 11 (2) ◽  
pp. 997-1014 ◽  
Author(s):  
Xiaowen Wang ◽  
Lin Liu ◽  
Lin Zhao ◽  
Tonghua Wu ◽  
Zhongqin Li ◽  
...  
Keyword(s):  
Quantitative Information ◽  
Google Earth ◽  
Tien Shan ◽  
Sar Interferometry ◽  
Western China ◽  
Mountain Ranges ◽  
Optical Images ◽  
Rock Glaciers ◽  
Altitudinal Limit ◽  
Northern Tien Shan

Abstract. Rock glaciers are widespread in the Tien Shan. However, rock glaciers in the Chinese part of the Tien Shan have not been systematically investigated for more than 2 decades. In this study, we propose a new method that combines SAR interferometry and optical images from Google Earth to map active rock glaciers (ARGs) in the northern Tien Shan (NTS) of China. We compiled an inventory that includes 261 ARGs and quantitative information about their locations, geomorphic parameters, and downslope velocities. Our inventory shows that most of the ARGs are moraine-derived (69 %) and facing northeast (56 %). The altitude distribution of ARGs in the western NTS is significantly different from those located in the eastern part. The downslope velocities of the ARGs vary significantly in space, with a maximum of about 114 cm yr−1 and a mean of about 37 cm yr−1. Using the ARG locations as a proxy for the extent of alpine permafrost, our inventory suggests that the lowest altitudinal limit for the presence of permafrost in the NTS is about 2500–2800 m, a range determined by the lowest ARG in the entire inventory and by a statistics-based estimation. The successful application of the proposed method would facilitate effective and robust efforts to map rock glaciers over mountain ranges globally. This study provides an important dataset to improve mapping and modeling permafrost occurrence in vast western China.

Distribution and morpho-thermal characteristics of rock glaciers in southern Peru: case, Cordilleras Huanzo and Chila

2020 ◽  
Author(s):  
Katy Medina ◽  
Edwin Loarte ◽  
Edwin Badillo ◽  
Hairo Leon ◽  
Francisco Castillo ◽  
...  
Keyword(s):  
Thermal Characteristics ◽  
Google Earth ◽  
High Mountain ◽  
Rock Glacier ◽  
Alos Palsar ◽  
Mountain Ranges ◽  
Thermal Range ◽  
Tropical Glaciers ◽  
The Pacific ◽  
Rock Glaciers

<p>Climate change generates significant impacts on high mountain regions, especially considering the sensitivity of tropical glaciers. However, information about rock glaciers are very scarce and there is very limited research in this field in Peru. Rock glacier concentrate mainly in the southern part of Peru where 95% of rock glaciers are located. Here we present for the first time an overview of rock glacier occurrence and characteristics in Peru.</p><p>The Cordilleras Huanzo and Chila are located in the mountain ranges in the southern region of Peru, Huanzo in the administrative region of Apurimac, Arequipa, Cusco and Ayacucho, while Chila in Arequipa. Both cordilleras extend from S 15°39'41.36" to 14°03'17.54" and W 73°24'12.55" to 71°27'113.20". For this study, remote sensing tools and geographic information system were applied, using images from Google Earth-Pro and SASPlanet, corrected DEM ALOS Palsar (12.5m), MERIT DEM (90m) and WorldClim data (1970-2000) 1 km<sup>2</sup>.</p><p>The results indicate that in the cordillera Huanzo there are 317 rock glaciers with a total area of 26.97 km<sup>2</sup> and in the cordillera Chila there are 289 rock glaciers with 17.96 km<sup>2</sup>. Concerning their activity or dynamic there are 295 intact (active and inactive) rock glaciers and 311 relict or fossil rock glaciers.</p><p>The results further indicate that rock glaciers are located in thermal ranges between -1.53°C and 3.97°C. The relict or fossil types are located in the thermal range between -1.34°C and 3.97°C, while intact types between -1.53°C and 2.56°C. The rock glaciers of the cordillera Huanzo are located at an average altitude of 4497 to 5221 m.a.s.l., while in the cordillera Chila at 4470 to 5454 m.a.s.l. The aspect is predominantly S to SW.</p><p>Rock glaciers contain ice which may represent a potential water reserve in arid regions in Southern of Peru. The greatest distribution of these resources is found in the Camana and Ocoña basins of the Pacific watershed with 38.1 km<sup>2</sup> of rock glacier area. In the Atlantic watershed, 6.8 km<sup>2</sup> of rock glaciers are located in the Alto Apurimac and Ocoña basins.</p>

scholarly journals Inventory, motion and acceleration of rock glaciers in Ile Alatau and Kungöy Ala-Too, northern Tien Shan, since the 1950s

2020 ◽  
Author(s):  
Andreas Kääb ◽  
Tazio Strozzi ◽  
Tobias Bolch ◽  
Rafael Caduff ◽  
Håkon Trefall ◽  
...  
Keyword(s):  
Sediment Transport ◽  
High Resolution ◽  
Tien Shan ◽  
Spatial And Temporal Variability ◽  
European Alps ◽  
Rock Glacier ◽  
Study Region ◽  
Rock Glaciers ◽  
The 1950S ◽  
Northern Tien Shan

Abstract. Spatio-temporal patterns of rock glacier creep have rarely been studied outside the densely populated European Alps. This study investigates the spatial and temporal variability of rock glacier motion in the Ile Alatau and Kungöy Ala-Too mountain ranges, northern Tien Shan. Over the study region of more than 3000 km2, an inventory of slope movements is constructed using a large number of radar interferograms and high-resolution optical imagery. The inventory includes more than 900 landforms, of which around 550 are interpreted as rock glaciers. Out of the active rock glaciers, 45 are characterised by a rate of motion exceeding 1 m/a. From these fast rock glaciers we select six and study them in more detail (Gorodetzky, Morenny, Archaly, Ordzhonikidze, Karakoram and Kugalan Tash rock glaciers) using offset tracking between airphotos, and historical and modern very high resolution optical satellite data. Most of them show an overall increase of decadal surface velocities from the 1950s onwards with speeds being roughly two to three times higher in recent years compared to the 1950s and 1960s. This development indicates a possible significant increase in sediment and ice fluxes through rock glaciers and implies that – when compared to glacier shrinkage – periglacial sediment transport in the region seems to gain importance relative to glacial sediment transport. Those rock glacier fronts reaching the valley floors show a strongly compressive flow regime, and changes in speeds further upstream affect them only in a damped way. The only rock glacier investigated in detail that does not exhibit an overall increase in speed since the 1950s is Gorodetsky where glacier retreat and dead-ice degradation seem to have decoupled the rock glacier from its supply by glacial sediments and ice.

scholarly journals Inventory and changes of rock glacier creep speeds in Ile Alatau and Kungöy Ala-Too, northern Tien Shan, since the 1950s

2021 ◽  
Vol 15 (2) ◽  
pp. 927-949
Author(s):  
Andreas Kääb ◽  
Tazio Strozzi ◽  
Tobias Bolch ◽  
Rafael Caduff ◽  
Håkon Trefall ◽  
...  
Keyword(s):  
High Resolution ◽  
Tien Shan ◽  
Spatial And Temporal Variability ◽  
European Alps ◽  
Material Transport ◽  
Rock Glacier ◽  
Study Region ◽  
Rock Glaciers ◽  
The 1950S ◽  
Northern Tien Shan

Abstract. Spatio-temporal patterns related to the viscous creep in perennially frozen sediments of rock glaciers in cold mountains have rarely been studied outside the densely populated European Alps. This study investigates the spatial and temporal variability of rock glacier movement in the Ile Alatau and Kungöy Ala-Too mountain ranges, northern Tien Shan, a region with particularly large and fast rock glaciers. Over the study region of more than 3000 km2, an inventory of slope movements was constructed using a large number of radar interferograms and high-resolution optical imagery. The inventory includes more than 900 landforms, of which around 550 were interpreted as rock glaciers. Out of the active rock glaciers inventoried, 45 are characterized by a rate of motion exceeding 100 cm/a. From these fast rock glaciers we selected six (Gorodetzky, Morenny, Archaly, Ordzhonikidze, Karakoram, and Kugalan Tash) and studied them in more detail using offset tracking between repeat aerial images and historical and modern high-resolution optical satellite data. Two of these rock glaciers showed a steady increase in decadal surface velocities from the 1950s onwards, with speeds being roughly 2 to 4 times higher in recent years compared to the 1950s and 1960s. Three rock glaciers showed similar accelerations over the last 1 to 2 decades but also phases of increased speeds in the 1960s. This development indicates a possible significant increase in current sediment and ice fluxes through rock glaciers and implies that their material transport in the region might gain geomorphodynamic importance relative to material transport by glaciers, assuming the latter decreases together with the regional glacier shrinkage. The study demonstrates how air and satellite image archives are exploited to construct one of the longest decennial times series of rock glacier speeds currently available. Our results are in line with findings from Europe about rock glacier speeds increasing with atmospheric warming and underline local variability of such an overall response.

Dynamics of rock glaciers of the Northern Tien Shan and the Djungar Ala Tau, Kazakhstan

1992 ◽  
Vol 3 (1) ◽  
pp. 29-39 ◽  
Author(s):  
Aldar P. Gorbunov ◽  
Sergei N. Titkov ◽  
Victor G. Polyakov
Keyword(s):  
Tien Shan ◽  
Rock Glaciers ◽  
Northern Tien Shan

scholarly journals STUDY OF THE DEPTH STRUCTURE OF SEISMICALLY ACTIVE ZONES BY THE METHOD OF MAGNETOTELLURIC SOUNDING

2021 ◽  
Vol 1 ◽  
pp. 137-143
Author(s):  
Elena A. Bataleva
Keyword(s):  
Deep Structure ◽  
Test Site ◽  
Tien Shan ◽  
Magnetotelluric Soundings ◽  
Mountain Ranges ◽  
Transition Zones ◽  
Conductivity Anomalies ◽  
Active Zones ◽  
Intermontane Basins ◽  
Northern Tien Shan

The paper presents the results of the analysis of data from magnetotelluric soundings performed in 2003-2020. A comparison of geoelectric models for the Chui and Kochkor basins of the Northern Tien Shan is shown. The main objective of the study is to identify patterns in the distribution of geoelectric inhomogeneities in the deep structure of the Bishkek geodynamic test site. Particular attention in geoelectric models was paid to the study of key objects of transition zones from mountain ranges to intermontane basins. The nature of crustal electrical conductivity anomalies is considered.

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